Rhododendron catawbiense ( Catawba Rhododendron )

Characteristics

Cultivar:	n/a
Family:	Ericaceae
Size:	Height: 5 ft. to 8 ft. Width: 6 ft. to 10 ft.
Plant Category:	shrubs,
Plant Characteristics:	seed start,
Foliage Characteristics:	evergreen,
Foliage Color:	dark green,
Flower Characteristics:	showy,
Flower Color:	pinks, purples,
Tolerances:

Requirements

Bloomtime Range:	Late Spring to Early Summer
USDA Hardiness Zone:	4 to 8
AHS Heat Zone:	Not defined for this plant
Light Range:	Deep Shade to Part Sun
pH Range:	4.5 to 6.5
Soil Range:	Sandy Loam to Some Clay
Water Range:	Normal to Moist

Plant Care

Fertilizing

How-to : Fertilization for Established Plants

Established plants can benefit from fertilization. Take a visual inventory of your landscape. Trees need to be fertilized every few years. Shrubs and other plants in the landscape can be fertilized yearly. A soil test can determine existing nutrient levels in the soil. If one or more nutrients is low, a specific instead of an all-purpose fertilizer may be required. Fertilizers that are high in N, nitrogen, will promote green leafy growth. Excess nitrogen in the soil can cause excessive vegetative growth on plants at the expense of flower bud development. It is best to avoid fertilizing late in the growing season. Applications made at that time can force lush, vegetative growth that will not have a chance to harden off before the onset of cold weather.

Light

Conditions : Partial Sun, Partial Shade

Part sun or part shade plants prefer light that is filtered. Sunlight, though not direct, is important to them. Often morning sun, because it is not as strong as afternoon sun, can be considered part sun or part shade. If you live in an area that does not get much intense sun, such as the Pacific Northwest, a full sun exposure may be fine. In other areas such as Florida, plant in a location where afternoon shade will be received.

Watering

Conditions : Moist and Well Drained

Moist and well drained means exactly what it sounds like. Soil is moist without being soggy because the texture of the soil allows excess moisture to drain away. Most plants like about 1 inch of water per week. Amending your soil with compost will help improve texture and water holding or draining capacity. A 3 inch layer of mulch will help to maintain soil moisture and studies have shown that mulched plants grow faster than non-mulched plants.

Planting

How-to : Pruning Flowering Shrubs

It is necessary to prune your deciduous flowering shrub for two reasons: 1. By removing old, damaged or dead wood, you increase air flow, yielding in less disease. 2. You rejuvenate new growth which increases flower production.

Pruning deciduous shrubs can be divided into 4 groups: Those that require minimal pruning (take out only dead, diseased, damaged, or crossed branches, can be done in early spring.); spring pruning (encourages vigorous, new growth which produces summer flowers - in other words, flowers appear on new wood); summer pruning after flower (after flowering, cut back shoots, and take out some of the old growth, down to the ground); suckering habit pruning (flowers appear on wood from previous year. Cut back flowered stems by 1/2, to strong growing new shoots and remove 1/2 of the flowered stems a couple of inches from the ground) Always remove dead, damaged or diseased wood first, no matter what type of pruning you are doing.

Examples: Minimal: Amelanchier, Aronia, Chimonanthus, Clethra, Cornus alternifolia, Daphne, Fothergilla, Hamamelis, Poncirus, Viburnum. Spring: Abelia, Buddleia, Datura, Fuchsia, Hibiscus, Hypericum, Perovskia, Spirea douglasii/japonica, Tamarix. Summer after flower: Buddleia alternifolia, Calycanthus, Chaenomeles, Corylus, Cotoneaster, Deutzia, Forsythia, Magnolia x soulangeana/stellata, Philadelphus, Rhododendron sp., Ribes, Spirea x arguta/prunifolia/thunbergii, Syringa, Weigela. Suckering: Kerria

How-to : Planting Shrubs

Dig a hole twice the size of the root ball and deep enough to plant at the same level the shrub was in the container. If soil is poor, dig hole even wider and fill with a mixture half original soil and half compost or soil amendment.

Carefully remove shrub from container and gently separate roots. Position in center of hole, best side facing forward. Fill in with original soil or an amended mixture if needed as described above. For larger shrubs, build a water well. Finish by mulching and watering well.

If the plant is balled-and-burlapped, remove fasteners and fold back the top of natural burlap, tucking it down into hole, after you've positioned shrub. Make sure that all burlap is buried so that it won't wick water away from rootball during hot, dry periods. If synthetic burlap, remove if possible. If not possible, cut away or make slits to allow for roots to develop into the new soil. For larger shrubs, build a water well. Finish by mulching and watering well.

If shrub is bare-root, look for a discoloration somewhere near the base; this mark is likely where the soil line was. If soil is too sandy or too clayey, add organic matter. This will help with both drainage and water holding capacity. Fill soil, firming just enough to support shrub. Finish by mulching and watering well.

How-to : Sow Seed

Now is the preferred time to sow seed.

Problems

Pest : Mealybugs

Small, wingless, dull-white, soft-bodied insects that produce a waxy powdery covering. They have piercing/sucking mouth parts that suck the sap out of plant tissue. Mealybugs often look like small pieces of cotton and they tend to congregate where leaves and stems branch. They attack a wide range of plants. The young tend to move around until they find a suitable feeding spot, then they hang out in colonies and feed. Mealybugs can weaken a plant leading to yellow foliage and leaf drop. They also produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal growth called sooty mold.

Prevention and Control: Isolate infested plants from those that are not. Consult your local garden center professional or the Cooperative Extension office in your county for a legal insecticide/chemical recommendation. Encourage natural enemies such as lady beetles in the garden to help reduce population levels of mealy bugs.

Pest : Whiteflies

Whiteflies are small, winged insects that look like tiny moths, which attack many types of plants. The flying adult stage prefers the underside of leaves to feed and breed. Whiteflies can multiply quickly as a female can lay up to 500 eggs in a life span of 2 months. If a plant is infested with whiteflies, you will see a cloud of fleeing insects when the plant is disturbed. Whiteflies can weaken a plant, eventually leading to plant death if they are not checked. They can transmit many harmful plant viruses. They also produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal growth called sooty mold.

Possible controls: keep weeds down; use screening in windows to keep them out; remove infested plants away from non-infested plants; use a reflective mulch (aluminum foil) under plants (this repels whiteflies); trap with yellow sticky cards, apply labeled pesticides; encourage natural enemies such as parasitic wasps in the garden; and sometimes a good steady shower of water will wash them off the plant.

Pest : Aphids

Aphids are small, soft-bodied, slow-moving insects that suck fluids from plants. Aphids come in many colors, ranging from green to brown to black, and they may have wings. They attack a wide range of plant species causing stunting, deformed leaves and buds. They can transmit harmful plant viruses with their piercing/sucking mouthparts. Aphids, generally, are merely a nuisance, since it takes many of them to cause serious plant damage. However aphids do produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface growth called sooty mold.

Aphids can increase quickly in numbers and each female can produce up to 250 live nymphs in the course of a month without mating. Aphids often appear when the environment changes - spring & fall. They're often massed at the tips of branches feeding on succulent tissue. Aphids are attracted to the color yellow and will often hitchhike on yellow clothing.

Prevention and Control: Keep weeds to an absolute minimum, especially around desirable plants. On edibles, wash off infected area of plant. Lady bugs and lacewings will feed on aphids in the garden. There are various products - organic and inorganic - that can be used to control aphids. Seek the recommendation of a professional and follow all label procedures to a tee.

Pest : Scale Insects

Scales are insects, related to mealy bugs, that can be a problem on a wide variety of plants - indoor and outdoor. Young scales crawl until they find a good feeding site. The adult females then lose their legs and remain on a spot protected by its hard shell layer. They appear as bumps, often on the lower sides of leaves. They have piercing mouth parts that suck the sap out of plant tissue. Scales can weaken a plant leading to yellow foliage and leaf drop. They also produce a sweet substance called honeydew (coveted by ants) which can lead to an unattractive black surface fungal growth called sooty mold.

Prevention and Control: Once established they are hard to control. Isolate infested plants away from those that are not infested. Consult your local garden center professional or Cooperative Extension office in your county for a legal recommendation regarding their control. Encourage natural enemies such as parasitic wasps in the garden.

Diseases : Blight

Blights are cause by fungi or bacteria that kill plant tissue. Symptoms often show up as the rapid spotting or wilting of foliage. There are many different blights, specific to various plants, each requiring a varied method of control.

Miscellaneous

Glossary : Border Plant

A border plant is one which looks especially nice when used next to other plants in a border. Borders are different from hedges in that they are not clipped. Borders are loose and billowy, often dotted with deciduous flowering shrubs. For best effect, mass smaller plants in groups of 3, 5, 7, or 9. Larger plants may stand alone, or if room permits, group several layers of plants for a dramatic impact. Borders are nice because they define property lines and can screen out bad views and offer seasonal color. Many gardeners use the border to add year round color and interest to the garden.

Glossary : Pacific Northwest

Pacific Northwest refers to plants native to parts of or all of the northwestern region of the United States, including Northern California, Oregon, Washington and British Columbia.

Glossary : Seed Start

Seed Start: easily propagated from seed.

Glossary : Shrub

Shrub: is a deciduous or evergreen woody perennial that has multiple branches that form near its base.

Glossary : pH

pH, means the potential of Hydrogen, is the measure of alkalinity or acidity. In horticulture, pH refers to the pH of soil. The scale measures from 0, most acid, to 14, most alkaline. Seven is neutral. Most plants prefer a range between 5.5 and about 6.7, an acid range, but there are plenty of other plants that like soil more alkaline, or above 7. A pH of 7 is where the plant can most easily absorb the most nutrients in the soil. Some plants prefer more or less of certain nutrients, and therefore do better at a certain pH.

Glossary : Flower Characteristics

Flower characteristics can vary greatly and may help you decide on a ""look or feel"" for your garden. If you're looking for fragrance or large, showy flowers, click these boxes and possibilities that fit your cultural conditions will be shown. If you have no preference, leave boxes unchecked to return a greater number of possibilities.

Glossary : Foliage Characteristics

By searching foliage characteristics, you will have the opportunity to look for foliage with distinguishable features such as variegated leaves, aromatic foliage, or unusual texture, color or shape. This field will be most helpful to you if you are looking for accent plants. If you have no preference, leave this field blank to return a larger selection of plants.

Glossary : Landscape Uses

By searching Landscape Uses, you will be able to pinpoint plants that are best suited for particular uses such as trellises, border plantings, or foundations.

Glossary : Tolerant

Tolerant refers to a plant's ability to tolerate exposure to an external condition(s). It does not mean that the plant thrives or prefers this situation, but is able to adapt and continue its life cycle.

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